Caulk and grout are building materials sometimes used interchangeably in certain tile applications and countertop installations. Both materials are bonding and sealing elements that have specific uses in home repairs and remodels. Caulk is a flexible and waterproof material, whereas grout dries to a hard, durable finish and may allow moisture to penetrate if not properly sealed. Caulk is best used in areas where flexibility is needed to preserve the integrity of seams. Grout works best to bond tile together and create a rock-hard surface impervious to movement.

Uses for Caulk

Caulk is a waterproof filler and sealant made from a base of flexible polymers. It is used to fill in gaps, cracks and breaks in various building materials such as walls, flooring, doors and windows, concrete, sinks and tubs. It creates an airtight seal that can protect against heat loss and water leakage, provide pest-control by keeping out unwanted critters and smooth out unsightly openings to create a seamless finished look. Caulk is applied using a caulk gun and is also sold in ready-to-use squeeze tubes.

Types of Caulk

  • Latex -- Also called painter's caulk or latex/acrylic caulk, latex caulk is the easiest kind to apply and can be painted over to match surroundings. Latex caulk cleans up easily and can be removed with soap and water before it hardens. This type of caulk is best for indoor applications.
  • Silicone -- Flexible and durable, silicone caulk is best used for nonporous surfaces and in gaps that expand and contract. This type of caulk cannot be painted over and comes in clear or neutral colors. Silicone caulk is an excellent choice for outdoor applications and can withstand extreme temperatures.
  • Acrylic Latex Silicone Blend -- This blend of caulk is easier to apply than silicone caulk and shares a similar durability. It's good for both indoor and outdoor applications and use with materials such as wood siding, brick, stone, windows and doors.
  • Specialty -- These caulks are targeted toward certain applications. Adhesive caulks both bind and seal; kitchen and bath caulk contains a material that fights against mold and mildew; roof sealant is used for minor roof leaks and repairs; concrete sealant can be used for driveways and sidewalks; fire-rated caulk is good for fireplaces and heat zones.

When to Apply Caulk

Caulk can be used with almost any material. Use caulk to fill in gaps, cracks and breaks in walls, and in between windows, doors, baseboards, wood siding and tiles. Use around tubs, tile and sinks to maintain waterproof seals and improve the aesthetic qualities of the room.

Uses for Grout

Grout is a mortar or paste that is used to fill gaps and crevices, especially between wall or floor tiles. Grout bonds and locks tiles into place and gives them a finished look while protecting ends from chipping and cracking. Grout is applied with a tool called a float that forces the material in between tile spaces and smooths it out evenly. A damp sponge helps remove residues.

Types of Grout

  • Cement-Based -- Made from a blend of Portland cement and powdered pigments mixed with water, cement-based caulk comes in varieties with and without sand. Sand bulks up grout and keeps it from shrinking in joints, making it a better choice for tiles with wider joints. Cement-based grout tends to be porous and prone to staining if left unsealed.
  • Epoxy -- Made of resin and a hardener, epoxy grout also comes in products with and without sand. Although more expensive than cement-based grout, epoxy grout is known for its stain resistance and hard, durable quality. This makes it ideal for heavy-traffic areas such as kitchen counters, backsplashes and floors.

When to Apply Grout

Use grout to connect, seal and repair floor tiles, kitchen tile walls and countertops, backsplashes, bathroom and tub tile, and any other areas that consist of tile.